Mask with integral cushion and forehead piece

ABSTRACT

A respiratory mask has an adjustable forehead support member that is simple and inexpensive to manufacture. The forehead support member may be adjusted by rotating a forehead pad about an off-center bore or by bending an angular adjustment beam. The mask has a mask cushion with an accordionate membrane having at least two hinged portions. The mask may be constructed with a mask frame, the mask cushion, and the forehead support member molded as one piece.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. Ser. No. 10/821,204, filed Apr.9, 2004, which claims the benefit of U.S. Provisional Application Ser.No. 60/461,414 filed Apr. 10, 2003, which are hereby incorporated hereinby reference in their entirety.

FIELD OF THE INVENTION

The present invention relates to a facial mask with an integral cushionand forehead piece used to supply breathable gas to a wearer's airways.

The invention has been developed primarily for use in supporting a nasalmask used in Continuous Positive Airway Pressure (CPAP) treatment of,for example, Obstructive Sleep Apnea (OSA) and other ventilationassistance treatments such as Non-Invasive Positive Pressure Ventilation(NIPPV) and will be described hereinafter with reference to thisapplication. However, it will be appreciated that the invention is notlimited to these particular uses.

BACKGROUND OF THE INVENTION

CPAP treatment is a common ameliorative treatment for breathingdisorders including OSA. CPAP treatment, as described in U.S. Pat. No.4,944,310, provides pressurized air or other breathable gas to theentrance of a patient's airways at a pressure elevated above atmosphericpressure, typically in the range of 4-20 cm H₂O. It is also known forthe level of treatment pressure to vary during a period of treatment inaccordance with patient need, that form of CPAP being known asautomatically adjusting nasal CPAP treatment, as described in U.S. Pat.No. 5,245,995.

NIPPV is another form of treatment for breathing disorders that caninvolve a relatively higher pressure of gas being provided in thepatient mask during the inspiratory phase of respiration and arelatively lower pressure or atmospheric pressure being provided in thepatient mask during the expiratory phase of respiration. In other NIPPVmodes, the pressure can be made to vary in a complex manner throughoutthe respiratory cycle. For example, the pressure at the mask duringinspiration or expiration can be varied through the period of treatment.

Typically, the ventilation assistance for CPAP or NIPPV treatment isdelivered to the patient by way of a nasal mask. Alternatively, a mouthmask full-face mask or nasal prongs can be used.

In this specification, any reference to CPAP treatment is to beunderstood as embracing all of the above-described forms of ventilationtreatment or assistance.

A CPAP apparatus broadly includes a flow generator for supplying acontinuous source of pressurized air or other breathable gas. Such aflow generator is typically a stand-alone unit having an electric motordriving a blower and is typically controlled by a servo-controller underthe control of a microcontroller unit. Alternatively, other supplies ofpressurized gas can be used. The flow generator is connected to the maskby a gas supply conduit or tube to supply the pressurized gas to aninterior of the mask. The mask or gas supply conduit generally includesa venting system to vent exhalation gases from the interior of the maskto the atmosphere. The mask is normally secured to the wearer's head bya headgear or straps. The straps are adjusted with sufficient tension toachieve a gas-tight seal between the mask and the wearer's face. Themask generally includes a forehead support to rest against the user'sforehead to support and stabilize the mask with respect to the user'sface and prevent the mask from exerting undue pressure on the user'snose when the straps are tensioned. Examples of nasal masks are shown inU.S. Pat. Nos. 4,782,832 and 5,243,971.

One problem that arises with the use of masks is that a single shape ofmask must be utilized for a large variety of users having differentlyshaped and sized heads and facial regions. Therefore, it is desirablefor the forehead support to be adjustable to alter an extension betweena forehead contacting portion of the forehead support and the maskframe, thereby accommodating a variety of users with a single maskconfiguration, while maintaining a comfortable fit and gas-tight sealfor each user. Additionally, an adjustable forehead support can beadjusted to position the gas supply conduit in a desired position withrespect to the user, such as to prevent the gas supply conduit fromcontacting the wearer's forehead or face and causing discomfort to theuser.

Adjustable forehead supports are known. See, for example, the adjustableforehead supports disclosed in U.S. Pat. No. 6,119,693 to Kwok et al.and PCT International Patent Application Publication No. WO 00/78384 toKwok et al., both assigned to the assignee of the present application.Both references disclose effective, durable forehead support mechanisms.However, these mechanisms require several components that increase theexpense of manufacturing such mechanisms and make the mechanisms moreappropriate for masks that will be used over an extended period of time,generally 3-6 months. Such mechanisms are relatively costly to use withmasks intended for single or short-term use.

There are circumstances where an inexpensive, disposable short-term usemask is appropriate. For instance, such a mask might be appropriateunder CPAP testing conditions where the testing is expected to last onlya few days or weeks. Such a mask might also be used for patientsadmitted to hospitals for short-term stays. Extended use masks requireperiodic disassembly, cleaning and disinfecting, and reassembly tomaintain sanitary conditions. The use of a disposable mask can eliminatesuch mask maintenance during extended treatment. Instead of performingthe mask maintenance at the periodic intervals, a user can just disposethe disposable mask at the proper intervals and use a new disposablemask. However, for it to be generally desirable to use a disposable maskin such extended term treatment, the cost of the mask must besufficiently low so as to compare favorably economically with theoverall cost of an extended use mask, including the cost of the extendeduse mask, as well as the time required and nuisance of the periodicmaintenance of the extended use mask.

Thus, there is a need for an inexpensive short-term use mask forproviding breathable gases to a patient, as during CPAP treatment. Toaccommodate a large variety of users comfortably with a single maskconfiguration and maintain a gas-tight seal for each user, the maskshould include a simple, easy to use adjustable forehead supportmechanism. The mask should be inexpensive enough to be disposable duringextended term CPAP treatment while comparing favorably economically tothe use of an extended term mask. The mask should also be inexpensiveenough to justify single-use. It is an object of the present inventionto provide such a mask.

SUMMARY OF THE INVENTION

The present invention addresses the above needs by providing arespiratory mask with an adjustable forehead support that is constructedwith few moving parts, and with as many parts as possible molded as onepiece or co-molded together in a single process. The present inventionprovides a mask that is not only low in cost, but also is easy to adjustdue to the simplicity of the adjustable forehead support.

A respiratory mask is provided having a mask frame, a mask cushionattached to the frame and a forehead support member integrally formedwith the mask frame. A plurality of strap attachment portions areprovided on the mask frame for attaching straps to the respiratory maskto secure the respiratory mask to a head and facial region of a user.The forehead support includes a forehead pad having a bore mounted overa forehead support member. The support pad bore has a number of sides,and the outer surface of the forehead support member has a cross-sectionwith a corresponding number of sides, such that the support pad can bemounted over the forehead support member in a number of distinct angularpositions corresponding to the number of sides of the support pad bore.An exterior surface of the support pad has a number of sidescorresponding to the number of sides of the support pad bore, eachexterior side preferably having a different spacing to an axis of theforehead support member than the other sides. In this manner, a numberof different extensions between a forehead-contacting portion of thesupport pad and the mask frame can be provided by changing the angularposition of the support pad with respect to the forehead support member.

An alternative embodiment of the mask includes a mask frame, molded in aflat configuration, having a cushion supporting portion, an air inletportion and a forehead support portion. A mask cushion is attached tothe mask frame cushion supporting portion. The forehead support portionand mask frame air inlet members are connected to the mask frame cushionsupporting portion by hinges such that the air inlet portion can befolded over the cushion supporting portion and the forehead supportportion can be folded over the air inlet portion with a cooperativelocking mechanism on the mask frame interlocking the components in afinal folded configuration ready for wearing. The forehead supportportion includes a pair of forehead support adjustment mechanismsadjustable as to height to adjust the extension of a forehead supportpad relative to the interlocked mask frame and mask cushion. The maskframe also includes portions for attaching to headgear or straps tosecure the mask to the head and facial region of the user.

A method of manufacturing a respiratory mask is provided includingmolding integrally in a generally flat configuration, a mask framehaving a cushion supporting portion, an air inlet portion and a foreheadsupport portion, with the forehead support portion and mask frame airinlet members being connected to the mask frame cushion supportingportion by hinges such that the air inlet portion can be folded over thecushion supporting portion and the forehead support portion can befolded over the air inlet portion and locked in a final wearableconfiguration. A mask cushion is also molded to or otherwise attached tothe mask frame cushion supporting portion.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will now be described, by way ofexamples only, with reference to the accompanying drawings in which:

FIG. 1 is a front perspective view of a first embodiment of a maskaccording to the invention;

FIG. 2 is a rear perspective view of the mask shown in FIG. 1;

FIG. 3 a is an enlarged perspective view of the forehead support of themask according to the first embodiment of the invention;

FIG. 3 b is an exploded view of the forehead support of the maskaccording to the first embodiment of the invention;

FIG. 3 c is a top plan view of the forehead pad of the mask according tothe first embodiment of the invention;

FIGS. 4 a-d are top plan views of the forehead support according to thefirst embodiment in each of four adjustable positions;

FIGS. 5 a-d are side elevational views of the forehead support accordingto the first embodiment in each of the four adjustable positions on auser's forehead;

FIG. 6 is a top plan view of an alternative embodiment of the foreheadpad;

FIG. 7 is a side elevational view of the mask according to the firstembodiment secured to a user;

FIGS. 8 a-c are schematic drawings depicting the interaction between thecushion and a user's facial region;

FIG. 9 is a front perspective view of an alternative embodiment of amask according to the invention;

FIG. 10 is a rear perspective view of the mask shown in FIG. 9;

FIG. 11 is a rear perspective schematic view of an alternativeembodiment of the present invention;

FIG. 12 is a rear elevational view of an alternative embodiment of thepresent invention;

FIGS. 13 a-d are partial schematic top plan views of an alternativeembodiment of a forehead support of the present invention;

FIGS. 14 a-d are partial schematic top plan views of an alternativeembodiment of a forehead pad of the present invention;

FIGS. 15 a-c are partial elevational views of an alternative embodimentof the forehead support of the present invention;

FIGS. 16 a and 16 b are partial side elevational schematic views of analternative embodiment of the forehead support of the present invention;

FIG. 17 is a front perspective view of another embodiment of theinvention, in a flat, unfolded state, wherein the respiratory mask ismolded as a single piece in a generally flat configuration to be foldedtogether for assembly;

FIG. 17 a is a rear perspective view of the embodiment configuration ofFIG. 17;

FIG. 18 is a rear perspective view of the embodiment of FIG. 17 whereinthe air inlet portion has been folded onto the cushion supportingportion;

FIGS. 19 a-c show top perspective detail views of a forehead supportadjustment mechanism of the embodiment of FIG. 17 with progressivestages of positioning of the forehead support adjustment mechanism;

FIGS. 20 a-c show bottom perspective detail views corresponding to FIGS.19 a-c;

FIG. 21 is a rear perspective view of the embodiment of FIG. 17 with theforehead support adjustment mechanisms assembled;

FIG. 22 is a rear perspective view of the embodiment of FIG. 21 with theforehead support adjustment mechanisms folded onto the forehead supportportion;

FIG. 23 is a front perspective view of the embodiment of FIG. 17 in afully assembled state (less straps and air hose);

FIGS. 24 a-b are side elevational views of the embodiment of FIG. 17showing two different forehead support adjustments;

FIG. 25 is a side elevational view of a further embodiment of thepresent invention incorporating the folding frame design of FIGS. 17-24and the forehead support of FIGS. 1-16;

FIG. 26 is a front, top perspective view of the embodiment of FIG. 25;

FIG. 27 is a rear, bottom perspective view of the embodiment of FIG. 26.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In the included figures a nasal mask is depicted, but the currentinvention is not intended to be limited to nasal masks. The aspects ofthe current invention are equally applicable to a mouth or full-facemask.

FIGS. 1 and 2 show front and rear perspective views of an embodiment ofthe present invention. A nasal mask 10 has a mask frame 20, strapattachment portions 30, a forehead support 40 including a foreheadsupport member 42 and a forehead pad 50, and a mask cushion 60. The maskalso has a single air inlet tube 70 mounted on the mask frame 20 forsupplying pressurized gas to an interior of the mask 10. Pressurized gasis supplied to the mask 10 by an air supply conduit (not shown)connected between the air inlet tube 70 and a pressurized air supply(not shown). As is known, an exhaust vent can be provided on the mask 10or air supply conduit for exhausting exhalation gases from an interiorof the mask. Other embodiments may have vents, elbows, pressure ports,or other attachments for items such as a sense tube or oxygen supplyport as further options. There may also be further attachment portionsfor straps or other types of headgear.

FIG. 3 a is an enlarged perspective view of the forehead pad 50 and FIG.3 b is an exploded view of the mask frame 20, forehead support member 42and the forehead pad 50. In this embodiment, forehead support member 42,is attached to and extends upwardly from mask frame 20. Forehead supportmember 42 includes a lower supporting surface 43, an upper supportingsurface 44 and an upright column 46 positioned between the supportingsurfaces 43 and 44 having four exterior sides 45. Two upper strapattachment portions 49 are mounted on opposing sides of an upper portionof the forehead support member 42 and are reinforced by brace member 47attached to and extending between an upper portion of the upper strapattachment portions 49 and the upper portion of the forehead supportmember 42. A position indicating marker 48 is attached to the bracemember 47. In the preferred embodiment, upright column 46 is solid toadd strength to the forehead support member 42. In alternativeembodiments, the upright column 46 can be hollow or can have astrengthening insert molded therein.

In this embodiment, the forehead pad 50 is an elastomeric pad, havingfour exterior sides 52, denoted individually as sides 521, 522, 523 and524, and an off-center bore 56. The off-center square bore 56 is definedby four inner surfaces 561, 562, 563, and 564, corresponding to sides521, 522, 523 and 524, respectively. The bore 56 is configured and sizedso as to be able to mount over the upright column 46 in a matingfashion. Upper supporting surface 44 and lower supporting surface 43 aresized to be somewhat larger than the size of bore 56 so that when theforehead pad is mounted over the forehead support member 42, the upperand lower supporting surfaces will retain the forehead pad in place onthe forehead support member 42. The elasticity of the forehead pad 50allows the forehead pad 50 to pass over the larger upper supportingsurface 44 when installing or removing the forehead pad 50 with respectto the forehead support member 42.

Since the bore 56 is off-center, a distance between an axis of the bore56 and the exterior sides 52 is different for each side 521, 522, 523,and 524, which in the embodiment shown, increases from side 521 to side522 to side 523 to side 524. See FIG. 3 c, which shows a distance d4 forside 524 greater than a distance d3 for side 523 greater than a distanced2 for side 522 greater than a distance d1 for side 521. In thisembodiment, the forehead pad can be mounted on the forehead supportmember in four different angular positions. In each angular position, adifferent side 52 will be facing toward the user to contact the user'sforehead. Since the distance between each side 52 and the axis of thebore 56 is different, changing the angular position of the forehead pad50 with respect to the forehead support member will alter the distancebetween the forehead support member 42 and the user's forehead, allowingthe forehead support 40 to be adjusted as desired for each user.

Each exterior side 52 has a corresponding position indicator 54, denotedindividually as position indicators 541, 542, 543 and 544, correspondingto sides 521, 522, 523 and 524, respectively. These position indicators54 are depicted as rounded projections, which provide a visual andtactile indicator of the position of the forehead pad 50 when mounted onthe forehead support member. As shown, position indicator 541 includesone raised projection, position indicator 542 includes two raisedprojections, position indicator 543 includes three raised projectionsand position indicator 544 includes four raised projections.Alternatively, the position indicators can be in the form of printedmarkings, notches, labels or other forms of visual and/or tactileindicators. The user is able to determine which angular position theforehead pad is in by determining which position indicator 54 is alignedwith the position indicating marker 48.

The bore 56 need not be of continuous cross-section, and need not extendfrom one end of the forehead pad 50 to the other, but rather may be openat only one end. Its configuration may also be tapered or have otherprovisions in order to effectively lock the forehead pad 50 to the mask10 so that it will resist moving from the chosen position when in use.Such locking effect may include the provision of stepped configurationalong the forehead support member 42 or the bore 56 such that there isengagement and interference between the two components. Alternativemechanisms for locking the adjusted forehead pad 50 to the foreheadsupport member 42 can also be used.

FIGS. 4 a, b, c, and d are top plan view of the mask 10 and FIGS. 5 a,b, c and d are side elevational views of the mask 10 positioned on auser, respectively illustrating the four angular positions of theforehead pad according to this embodiment of the invention. FIGS. 4 aand 5 a illustrate the first angular position, appropriate for a userhaving a protuberant forehead. The forehead pad 50 has been rotatedcounterclockwise from the first position to the second positionillustrated in FIGS. 4 b and 5 b. This position is appropriate for aless protuberant forehead than in position 1. The forehead pad 50 hasbeen further rotated counterclockwise from the second position to thethird position illustrated in FIGS. 4 c and 5 c. This position isappropriate for a slightly receding forehead. Finally, the forehead padhas been rotated counterclockwise from the third position to the fourthposition illustrated in FIGS. 4 d and 5 d. This position is appropriatefor users having a more receding forehead than illustrated in FIG. 5 c.Although only four positions are shown, fewer or greater than fourpositions can be provided by suitably altering the number of sides 45,52 and 56, with a distance between each side 52 and an axis of theforehead support member 42 being different.

In an alternative embodiment shown in FIG. 6, the forehead pad 50 can becam-shaped and have a toothed off-center bore 56 adapted to engage asimilarly toothed forehead support member 42 to provide a greaterresolution of adjustment, Alternatively, if pad 50 is retained tosupport 42 by press fit, a generally continuously variable adjustabilityof the distance from the forehead contacting surface of the pad 50 tothe mask frame 20.

FIG. 7 illustrates a nasal mask 10 of the present invention being wornby a user. Mounting straps 32 are attached to the strap attachmentportions 30, to attach the nasal mask to the user's head. The foreheadpad 50 contacts the forehead. The mask cushion 60 seals the mask frame20 to the facial region of the user. The mask cushion 60 is shaped tosubstantially conform to the facial region of the user. However, theshape of the facial regions of different users varies and the adjustableposition of the forehead pad 50 may not be optimal for all users.Therefore, it is desirable for the mask cushion 60 to be flexible andresilient to seal the mask frame 20 to the facial regions of a varietyof users.

FIGS. 8 a, 8 b and 8 c are schematic diagrams depicting the accordionateconfiguration and behavior of the mask cushion 60. Cushion 60 includes aface contacting portion 66 connected to a main body 68 of the cushion 60by cushion hinged portions 62 and 64. If a portion of the mask frame 20is close to the facial region of the user, the included angles of thetwo hinged portions 62, 64 will decrease, allowing the face contactingportion 66 to draw closer to the mask frame without causing discomfortto the user. If a portion of the mask frame 20 is not close to thefacial region of the user, the included angles of the two hingedportions 62, 64 will increase, allowing the face contacting portion 66to extend from the mask frame while continuing to maintain a seal withthe facial region of the user. FIG. 8 a depicts a condition in which theangle between the mask frame 20 and the facial region of the user issubstantially optimized. FIG. 8 b depicts a condition in which the upperportion of the mask frame 20 is closer to the facial region of the userthan the lower portion, and the upper portion of the face contactingportion 66 of the cushion is closer to the cushion main body 68 than thelower portion of the face contacting portion 66 to accommodate for this.FIG. 5 c depicts a condition opposite to the condition in FIG. 8 b inwhich the lower portion of the mask frame 20 is closer to the facialregion of the user than the upper portion, and the lower portion of theface contacting portion 66 of the cushion is closer to the cushion mainbody 68 than the upper portion of the face contacting portion 66 toaccommodate for this.

FIGS. 9 and 10 show front and rear perspective views of an alternativeembodiment of the present invention. The nasal mask 10 of thisembodiment is similar to the embodiment shown in FIGS. 1 and 2 but has amask frame 20 having a slightly different shape and configuration toimprove moldability of the frame, as well as to improve the aestheticappearance of the frame. This embodiment also has strap attachmentportions 30, a forehead support 40 including a forehead support member42 and a forehead pad 50, a mask cushion 60 and a single air inlet tube70 mounted on the mask frame 20 for supplying pressurized gas to aninterior of the mask 10.

FIG. 11 is a rear perspective schematic view of an alternativeembodiment of the present invention. In the nasal mask 10 of thisembodiment, an air inlet tube 72 is mounted to the top of the mask frame20 and has a square outer cross-section so as to act as the foreheadsupport member 42 of the previous embodiments. As with the previousembodiments, the forehead pad 50 can be placed over the air inlet tubein a plurality of different angular positions to alter a distancebetween the air inlet tube/forehead support member 72 and allow the maskto be adjusted for each user.

FIG. 12 is a rear elevational view of an alternative embodiment of thepresent invention.

FIGS. 13 a-d are partial schematic top plan views of an alternativeembodiment of the forehead support 40. In this embodiment, the foreheadsupport member 42 is configured to have a U-shaped cross-section. Anopen end of the U-shaped cross-section is shown as facing toward theuser but can be oriented away from the user as well. The U-shape canreduce material required for the forehead support member 42 whileretaining the necessary strength. FIGS. 13 a-d show the differentangular positions of the forehead pad 50 corresponding respectively tothe positions shown in FIGS. 4 a-d and 5 a-d.

FIGS. 14 a-d are partial schematic top plan views of an alternativeembodiment of the forehead pad 50 positioned on the forehead supportmember 42 of the embodiment shown in FIGS. 13 a-d. The forehead pad 50of this embodiment is not shaped as a rectangle with flat exteriorsides. Rather, each exterior side 52 of the forehead pad is generallyU-shaped in cross-section with the open end facing outward. Although thebore 56 is positioned generally in a center of a central portion 59 ofthe forehead pad 50, the two legs 58 of the U-shaped cross-section ofeach exterior side 52 have a different height. Because of thisconfiguration, the adjustment of the forehead support 40 can be alteredas described above by changing the angular orientation of the foreheadpad 50 on the forehead support member 42. FIGS. 14 a-d show thedifferent angular positions of the forehead pad 50 correspondingrespectively to the positions shown in FIGS. 4 a-d, 5 a-d and 15 a-d.This configuration of forehead pad 50 can reduce the amount of materialrequired to make the pad and can also minimize an area of contact of theforehead pad 50 with the user to increase the comfort of the user.

FIGS. 15 a-c are partial elevational views of an alternative embodimentof the forehead support 40. In this embodiment, the forehead supportmember 42 (or air inlet tube 72) has an extended height to provide for aplurality of different elevational positions for the forehead pad 50. Inthe embodiment shown, the forehead support member 42 includes threeseparate elevational adjustment positions 120 bounded on each side byposition retaining flanges 122. The forehead pad can be moved to any oneof the elevational adjustment positions 120 to provide a desiredelevational position of the forehead pad 50 on the nasal mask 10 withrespect to the user. The position retaining flanges 122 are larger thanthe bore 56 in the forehead pad 50 to prevent the forehead pad 50 frommoving undesirably up and down the forehead support member 42 once ithas been adjusted but due to the flexibility of the forehead pad 50, itcan be moved over a position retaining flange 122 by applying sufficientforce to the forehead pad 50. The force required to move the foreheadpad to a different elevational adjustment position can be altered byaltering the size of the position retaining flanges 122 with respect tothe bore 56 and/or by changing the flexibility of the forehead pad 50.Three elevational positions of the forehead pad 50 are shownrespectively in FIGS. 15 a, 15 b and 15 c. The number of elevationaladjustment positions 120 can be altered as desired. In a modifiedversion of this embodiment, retaining flanges can be positioned on theforehead pad 50 to engage grooves or other structure on the foreheadsupport member 42.

FIGS. 16 a and 16 b are partial side elevational schematic views of analternative embodiment of the forehead support 40. In this embodiment,the forehead support member 42 is tapered along its length. Because theforehead pad 50 is flexible, it can be moved to a desired position alongthe forehead support member and the forehead support member willcorrespondingly expand the bore 56 of the flexible forehead pad 50,creating a friction fit between the forehead pad 50 and the foreheadsupport member 42 that will retain the forehead pad 50 in the adjustedposition. FIG. 16 a shows the forehead pad 50 in an elevated positionwith respect to the forehead support member 42 where there is a minimalfriction fit and FIG. 16 b shows the forehead pad 50 in a loweredposition with respect to the forehead support member 42 where there isan increased frictional fit. Thus, this embodiment allows infiniteelevational positioning of the forehead pad 50 along a given range ofthe forehead support member 42, as opposed to the discrete positioningprovided by the embodiment of FIGS. 15 a-c. The magnitude of retainingforce of the friction fit between the forehead pad 50 and the foreheadsupport member 42 can be altered by altering the size and shape of thebore 56, the flexibility, material or surface finish of the forehead pad50, or the taper, size, shape, material or surface finish of theforehead member 42. In one embodiment, a retaining flange can beprovided at a bottom portion of the forehead support member 42 toprovide a positive bottom stop to the elevational adjustment of theforehead pad 50.

FIGS. 17-24 illustrate another embodiment of the invention. In thisembodiment, the respiratory mask is molded as a single piece in agenerally flat configuration and folded together for assembly. FIG. 17is a front perspective view of the mask frame in the flat, unfoldedstate. The mask frame 20 includes a cushion supporting portion 80, anair inlet portion 90 and a forehead support portion 100. An integralhinge 92, also called a “living hinge”, is molded between the cushionsupporting portion 80 and the air inlet portion 90. An integral hinge102 is molded between the cushion supporting portion 80 and the foreheadsupport portion 102. In this manner, both the air inlet portion 90 andthe forehead support portion 102 can be folded with respect to thecushion supporting portion 80. A sealing member 82 (see FIG. 17 a) isprovided around a periphery of the cushion supporting member 80 andadapted to sealingly engage the air inlet portion 90 such that when theair inlet portion 90 is folded over onto the cushion supporting portion80, a gas-tight seal is formed between those two portions to seal aninterior of the mask 10. A latch mechanism 94 is attached to a distaledge of the air inlet portion 90 and is adapted to engage a lip 84 onthe cushion supporting portion when the two components are foldedtogether to latch the two components in the folded position. See FIG.18, which is a rear perspective view of the mask 10 wherein the airinlet portion 90 has been folded onto the cushion supporting portion 80and latched in place.

The forehead support portion 100 has a main body portion 104 and aforehead pad mounting portion 108 interconnected by an offset portion106 to offset the forehead pad 110 with respect to the main body portion104. The degree of offset, if any, can be altered as desired for thespecific application. Rib 109 between the main body portion 104 and theoffset portion 106 adds strength to the forehead support portion 100.

The forehead support portion 100 can utilize the forehead supportmechanism 40 discussed above, as shown in FIGS. 25-27 and discussed inmore detail below. Alternatively, a nonadjustable forehead pad 110 canbe attached to the forehead support portion 100 using methods describedherein or molded integrally therewith. In such an embodiment, it isdesirable to provide an alternative mechanism for adjusting the foreheadpad with respect to the mask frame 20. In one such embodiment, theforehead support portion 100 is provided with a pair of forehead supportadjustment mechanisms 130. Each forehead support adjustment mechanism130 is preferably molded integrally with the forehead support portion100, although this is not required, and includes an elongated adjustmentchannel member 132 attached at one end to the forehead support portion100 by hinge 134. A foldable adjustable height member 138 is attached atanother end of the adjustment channel member 132 by hinge 136. Theadjustable height member 138 preferably, though not necessarily,includes a side segment 140, top segment 144 and side segment 148connected together by hinges 142 and 146, respectively, so as to befoldable with respect to one another. See FIGS. 17-18. Alternatively,top member 144 and hinge 146 can be omitted so that side segment 140 isdirectly connected to side segment 148 by hinge 142. See FIGS. 19-24. Anadjustment tab 152 is connected to side member 148 by hinge 150 and isconfigured and arranged for adjustable engagement with adjustmentchannel member 132. See FIGS. 19 a-c, which show top perspective detailviews of the forehead support adjustment mechanism 130 with progressivestages of positioning of the forehead support adjustment mechanism 130,and 20 a-c, which show corresponding bottom perspective detail viewsthereof.

Each elongated adjustment channel member 132 includes a channel 154including a tab insertion portion 156 and an adjustment portion 158. Theadjustment portion 158 of channel 154 includes a pair of sets ofuniformly spaced opposed detent slots 160 extending from side walls ofthe channel 154 inward toward one another. The adjustment tab 152includes a top retaining portion 162 connected to an adjustment fixingportion 164 connected to a bottom retaining portion 166. See FIGS. 19and 20. The bottom retaining portion 166 can be grooved (see FIGS. 19 aand 20 b), ridged or otherwise textured, as can top retaining portion162 to increase a user's grip on the adjustment tab 152 duringadjustment. The adjustment fixing portion 164 includes a pair of sets ofoutwardly facing detent lugs 168 spaced, configured and dimensioned soas to be able to uniformly engage the detent slots 160 of channel 154 ina temporarily fixed adjustment position until sufficient force isapplied to move the detent lugs 168 with respect to the detent slots160.

In a preferred embodiment, a width of the bottom retaining portion 166of the adjustment tab 152 is less than or equal to a width of the tabinsertion portion 156 of the channel 154 and a width of the topretaining portion 162 of the adjustment tab 152 is greater than a widthof the tab insertion portion 156 of the channel 154 so as to permitinsertion of the adjustment tab 152 into the tab insertion portion 156(see FIGS. 19 a and 20 a) until the top retaining portion 162 of theadjustment tab 152 contacts the adjustment channel member 132 to preventfurther insertion (see FIGS. 19 b and 20 b). On the other hand, thewidth of the bottom retaining portion 166 of the adjustment tab isgreater than a minimum width between the opposing sets of detent slots160 of channel 154 so that when the adjustment tab 152 is moved alongthe length of the channel 154 from out of the tab insertion portion 156into the adjustment portion 158 (see FIGS. 19 c and 20 c), the detentslots 160 engage the bottom retaining portion 166 of adjustment tab 152to retain adjustment tab 152 in the channel 154 until the adjustment tab152 is again moved lengthwise along the channel 154 back into the tabinsertion portion 156 (see FIGS. 19 b and 20 b). Adjusting the positionof the adjustment tab 152 along the length of the channel 154 allows theoverall height of the adjustable height member 138 to be altered withrespect to the adjustment channel member 132 and thus, the foreheadsupport portion 100 of the mask, to adjust the height of the foreheadsupport pad, as will be discussed below in further detail. FIG. 21 is arear perspective view of the mask of this embodiment, with theadjustment tabs 152 positioned in the adjustment portions 158 of thechannels 154, respectively.

A minimum inner width between the closest portions of opposed sets ofthe detent slots 160 of the channel 154 is somewhat smaller than amaximum exterior width of opposed sets of the detent lugs 168 of theadjustment tab 152 so that engagement between the detent slots 160 ofchannel 154 and the detent lugs 168 of the adjustment tab 152 willtemporarily fix the adjustment tab 152 in a desired lengthwise positionin the adjustment portion 158 of the channel 154 until sufficient forceis applied to overcome such engagement. The force required is determinedby a trade-off between balancing the minimum force required to maintainthe adjustment tab 152 in a desired adjusted position in the channel 154when the mask is being worn by the user with the maximum force desiredto allow the user the change the adjustment of the adjustment tab 152.These forces can be altered by altering the magnitude of the engagementbetween opposing detent slots/detent lugs of the channel 154 andadjustment tab 152, respectively, by altering dimensions of therespective detent slot/detent lugs and altering the number and/or shapeof the respective detent slots/detent lugs, as well as by altering thematerial and/or rigidity of the respective detent slots/detent lugs. Thepositioning of the detent slots and detent lugs on the respectivecomponents can be reversed and alternative detent configurations can beused.

FIG. 22 is a rear perspective view of the mask of this embodiment wherethe forehead support adjustment mechanisms 130, through hinges 134, havebeen folded down onto a rear surface of the forehead support portion 100of mask frame 20. Forehead support portion 100 can include stabilizingportions 170 (see FIG. 21), such as raised ridges or walls, slots orother structure, to engage the adjustment channel members 132 or otherportions of the forehead support adjustment mechanisms 130 to providelateral and other support to the mechanisms 130 when they are in theirfinal folded position. At this point, the cushion supporting portion80/air inlet portion 90 folded subassembly can be folded toward theforehead support portion 100 of the mask until subassembly comes intocontact with the upstanding portion of the adjustable height members138, with the adjustable height members 138 positioned on opposing sidesof the cushion supporting portion 80/air inlet portion 90 foldedsubassembly and between the forehead support portion 100 and the cushionsupporting portion 80/air inlet portion 90 folded subassembly. See FIGS.23-24. In the shown embodiment, the adjustable height members 138 areshown as contacting a surface 96 of the air inlet portion 90, althoughthis can be altered as desired so that the adjustable height members 138contact other portions of the cushion supporting portion 80/air inletportion 90 folded subassembly.

By altering the lengthwise positions of the adjustment tabs 152 in theadjustment portions 158 of the channels 154, the height of theadjustable height members 138 can be adjusted with respect to theforehead support portion 100, thereby altering an angle θ (at hinge 102)between the forehead support portion 100 and the cushion supportingportion 80/air inlet portion 90 folded subassembly, and thus, altering acorresponding relative height between the forehead pad 110 and thecushion 60. Compare FIGS. 24 a and 24 b. The height of adjustable heightmember 138 is higher in FIG. 24 a because the adjustment tab 152 ispositioned in the adjustment portion 158 of channel 154 nearer hinge 136in FIG. 24 a, thereby resulting in the forehead pad 110 being relativelypositioned more toward the front of the mask than in FIG. 24 b to betteraccommodate a user having a more protuberant forehead. For instance, theadjustment shown in FIG. 24 a corresponds more with a user as shown inFIG. 5 b while the adjustment shown in FIG. 24 b corresponds more with auser as shown in FIG. 5 c. The user can easily adjust the relativeposition of the forehead pad 110 through manual adjustment of the heightof the adjustable height member 138 by moving the adjustment tab 152 inthe channel 154. In this embodiment, the angle of the forehead pad 110will change with respect to the user within the range of adjustmentprovided. However, this is accommodated by the resiliency of theforehead pad and can be altered within certain parameters by alteringthe angle of upright portion 46, and/or a user-contacting portion of theforehead pad 110 with respect to a plane of forehead support portion100. Alternatively, hinge 102 can be replaced by a double hinge tominimize relative angle changes in the forehead pad 110 as the relativeheight of the forehead pad is adjusted. Alternatively, the forehead padcan have a cylindrical surface to accommodate varying angles of contactwith the forehead.

Strap attachment portions 49 and 30 are provided on the forehead supportportion 100 and the cushion supporting portion 80 or air inlet portion90 for attaching to headgear or straps to secure the mask to the headand facial region of the user. Although the adjustment mechanisms 130are shown as being attached to the forehead support portion 100,alternative embodiments can be constructed by attaching the adjustmentmechanisms to the cushion support portion 80 and/or the air inletportion 90 and contacting against the forehead support portion 100.Alternatively, the use of a single adjustment mechanism or three or moreadjustment mechanisms is contemplated, as well as the use of separatelymolded adjustment mechanisms.

FIGS. 25-27 show a further embodiment of the present inventionincorporating aspects from the mask of FIGS. 17-24 and the foreheadsupport of FIGS. 1-16. In this embodiment, the forehead support portionsupports a forehead support member 42 and forehead pad similar to theembodiments shown in FIGS. 1-16. This embodiment also shows use of themask frame and forehead adjustment mechanisms of the embodiment shown inFIGS. 17-24. Thus, this embodiment gives a wider range of forehead padadjustability than either of the other two groups of mask embodimentsalone. In a modification of this embodiment, the forehead supportadjustment mechanisms 130 could be removed or replaced by generallyfixed members to combine the one-piece, disposable frame aspects ofFIGS. 17-24 with the forehead pad adjustment of FIGS. 1-16.

In order to enable the mask to be molded as one piece, allowance must bemade for variation in the desirable characteristics of the differentsections of the molding. For example, the mask frame 20 must be rigid,but the mask cushion 60 must be flexible enough to provide comfort andgood sealing properties while the forehead support member 42 must beresilient. To make the mask out of one material, such as polypropylene,while providing the differing levels of flexibility desired in thevarious components, the molding process can provide a changing gradientof material density, as can be achieved by forms of gas assistedinjection molding, resulting in a change in rigidity. Another option,which could be used in addition to the changing gradient of materialdensity, is the use of a continuous gradient of material thickness or bystepped contours or introduction of ribbing to provide reinforcement incertain areas where more rigidity is required.

An alternative construction can involve the incorporation of a separatemask cushion 60 to the mask frame 20. The mask cushion 60 can be made ofmaterial different to the mask frame 20 or can be made of the samematerial and may be attached by using any of the methods known in theart, such as friction fit, strapping, clips, or adhesive. Alternatively,the mask cushion 60 can be overmolded onto the mask frame or co-moldedwith the mask frame 20 in accordance with methods known in the art ofmolding. In such examples, placement of appropriate channeling in themask frame 20 allows for bleed-through of cushion molding material so asto achieve enhanced attachment of the mask cushion 60 to the mask frame20. This can be especially desirable if the mask cushion 60 is made of amaterial that does not readily form a chemical bond with the material ofthe mask frame 20. This technique may also be used to provide evensofter material between the mask frame 20 and the user at certaincontact points, a decorative effect, or visually vivid and tactilelabeling. The key polymers capable of incorporating living hinges andwhich would be suited to this application are polypropylene andstyrene-butadiene copolymers such as K-Resin®.

It is intended that various features of the various embodimentsdescribed above can be combined to create different embodiments of thenasal mask of the present invention. The embodiments describe above areexemplary only and are not exhaustive of the scope of the invention. Itis also intended that changes and modifications can be made to theembodiments described above without departing from the scope of theinvention.

1. A method of manufacturing a respiratory mask for delivering apressurized flow of breathable gas to a patient, the method comprising;molding integrally a mask frame, an inlet portion comprising an inletfor the flow of pressurized breathable gas, a forehead support member, afirst hinge connecting the mask frame to the inlet portion, a secondhinge connecting the mask frame to the forehead support member, and acooperative interlocking structure on the mask frame and the inletportion; folding the mask frame relative to the inlet portion;interlocking the cooperative interlocking structure so that the maskframe is locked in a position relative to the inlet portion; and foldingthe forehead support member relative to the mask frame so that the inletportion is interposed between the forehead support member and the maskframe.
 2. A method according to claim 1, further comprising attaching acushion to the mask frame.
 3. A method according to claim 2, whereinattaching a cushion to the mask frame comprises integrally molding thecushion with the mask frame.
 4. A method according to claim 2, whereinattaching the cushion to the mask frame comprises overmolding orco-molding the cushion with the mask frame.
 5. A method according toclaim 2, wherein attaching the cushion to the mask frame comprisesattaching the cushion to the mask frame by a friction fit, a strap, aclip, or adhesive.
 6. A method according to claim 1, further comprisingmolding a forehead pad integrally with the forehead support member.
 7. Amethod according to claim 1 further comprising molding a folding beamintegrally with the forehead support member, wherein, after the foreheadsupport member is folded relative to the mask frame, the angle of theforehead support member relative to the interlocked mask frame and inletportion may be adjusted by altering an angle of the foldable beam.
 8. Amethod according to claim 7, wherein molding the folding beam comprises:molding a third integral hinge between the forehead support member and afirst end of the foldable beam; molding at least one fourth integralhinge between the first end of the foldable beam and a second end of thefoldable beam; and molding a fifth integral hinge between the at leastone fourth integral hinge and the second end of the foldable beam.
 9. Amethod according to claim 8, wherein the foldable beam comprises achannel between the third living hinge and the at least one fourthliving hinge and the second end of the foldable beam comprises a tabconfigure to be inserted in the channel.
 10. A method according to claim9, wherein the tab is configured to be retained in a plurality ofdiscrete positions in the channel.
 11. A respiratory mask for deliveringa flow of pressurized breathable gas to a patient, comprising: a maskframe; an inlet portion comprising an inlet for the flow of pressurizedbreathable gas, the inlet portion being connected to the mask frame by afirst living hinge; and a forehead support member connected to the maskframe by a second living hinge, wherein the mask frame and the inletportion comprise interlocking structure to lock the mask frame and theinlet portion together when the mask frame is folded relative to theinlet portion and the inlet portion is interposed between the foreheadsupport member and the mask frame when the mask frame is folded relativeto the forehead support member.
 12. A respiratory mask according toclaim 11, further comprising a cushion supported by the mask frame. 13.A respiratory mask according to claim 12, wherein the cushion isintegrally molded with the mask frame, overmolded to the mask frame,co-molded with the mask frame, or attached to the mask frame by afriction fit, a strap, a clip, or adhesive.
 14. A respiratory maskaccording to claim 11, further comprising a folding beam, wherein thefolding beam is connected at a first end to the forehead support memberby a third living hinge and, after the forehead support member is foldedrelative to the mask frame, the angle of the forehead support memberrelative to the interlocked mask frame and inlet portion may be adjustedby altering an angle of the foldable beam.
 15. A respiratory maskaccording to claim 14, wherein the folding beam comprises at least onefourth integral hinge between the first end of the foldable beam and asecond end of the foldable beam and a fifth integral hinge between theat least one fourth integral hinge and the second end of the foldablebeam.
 16. A respiratory mask according to claim 15, wherein the foldablebeam comprises a channel between the third living hinge and the at leastone fourth living hinge and the second end of the foldable beamcomprises a tab configure to be inserted in the channel.
 17. Arespiratory mask according to claim 16, wherein the tab is configured tobe retained in a plurality of discrete positions in the channel.
 18. Arespiratory mask according to claim 17, wherein the tab comprises aplurality of detent lugs and the channel comprises a plurality of detentslots.
 19. A respiratory mask according to claim 11, wherein theforehead support portion comprises an offset portion configured to atleast partially over the mask frame when the mask frame is foldedrelative to the forehead support member.
 20. A respiratory maskaccording to claim 11, further comprising strap attachment portionsprovided to the forehead support member.